


The Illusionist's Apprentice

by Cilare



Category: Kingdom Hearts
Genre: And Kairi is tired of waiting and being a plot device, Badass Kairi, But mostly fluff, Characters are older than in canon, F/M, Fluff and Angst, I will probably add more tags when I think about them, Post Kingdom Hearts I, Selphie has a bookshop, The Hollow Bastion Restoration Committee, The plot diverges from canon after a while, Zexion is cute when he smiles but he will never admit it, medium to slow burn, some drama
Language: English
Status: In-Progress
Published: 2019-02-02
Updated: 2019-03-09
Packaged: 2019-10-20 23:07:13
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 7
Words: 8,737
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17631461
Author URL: https://archiveofourown.org/users/Cilare/pseuds/Cilare
Summary: Kairi waits for Sora and Riku to return, powerless and unable to leave the Destiny Islands. It's when a stranger in a black coat appears in the small bookshop, asking about magic tomes, that she decides this is her chance to do something about her situation.As occupied as Zexion is with his investigation for the Organization XIII, his side-project has always been magic. So when a girl offers him a magic tome in exchange for some teaching, he is tempted.- - -Zexion x Kairi fic, in which Kairi takes the reins of her future thanks to a deal with a certain nobody. Relatively slow-burn, canon-divergent after a certain point. Characters are older than in canon.





	1. Magic tomes are very particular, you see.

**Author's Note:**

> So, first things first, I’m aging up the characters a little. Kairi and Selphie will be around 17, and Zexion, Riku and Sora are perhaps a year or two older. I do not plan on having any smut, this is mostly for my own comfort when writing romance. Having said that, expect this fic to be fluffy with a healthy dose of drama and angst, but the main course will still be fluff. I’ll try my best to stay in-character and in-universe, but there are things I’m going to add because I wanted the plot to go a certain way and I hope you enjoy this nevertheless.

The dark corridor appears as the nobody flicks his wrist, the darkness folding to his wishes and closing behind him as he leaves the World that Never Was. A few steps later it opens again, but now the sunlight has changed and Zexion knows, without a shadow of a doubt, that he is in the world he was looking for. 

The sunlight is golden and warm against his dark coat, the breeze is cool enough and the few people on the street watch him curiously, yes, but no one stops him as he looks for the small book shop he's heard of. It’s mostly a rumor by now but he’s nothing if not curious and magic tomes are rare enough that the distraction might be worth it. He tries not to look disappointed as he finally faces the small, wooden place, and he steps inside. 

White curtains dim the light as soon as the door closes with a jingle and the young woman behind the counter turns towards him with a blinding smile. She’s been talking with somebody else, probably the owner of the jacket Zexion can see behind a few shelves, but the conversation stops as he finds himself being the center of attention. 

“Hello! I’ve never seen you around, are you looking for the new novels too?”

In another life, when he still had a heart, he might have been immensely uncomfortable at the girl’s closeness. Right now he just wants the exchange to end. 

“No, not the novels…”

The girl interrupts him with a dramatic sigh and shakes her head. “It’s a shame. History books?” She asks, looking cheery again. “I’m Selphie, by the way, and my friend over there is Kairi.”

Another feminine head appears behind the shelves and waves at him. Zexion simply nods, already considering if it wouldn’t be better to cast an illusion that hides him from view and search by himself. 

“I’m looking for books on magic. I don’t mean party tricks.” He explains, as the girls cross a curious look. When he turns around, however, Kairi is again hidden from views. 

Selphie thinks about it for a second, then shrugs as she very obviously tries and fails to hide her laughter. “None that I know of. We have fantasy novels, though.” 

Zexion very pointedly doesn’t sigh. “And what about old books?”

 

By the time Zexion leaves the bookshop he’s already exercised most of his restraint for the week. He’s lost nearly a full morning and he cannot afford these kinds of failures. He’s just focused his mind on an image of the World that Never Was, a moment away from opening the corridor, when the sound of steps makes him turn around. The other girl, Kairi, is there, and she’s clutching an old tome that has seen better days. 

“Have you ever seen a real book about magic?” She asks him, after checking there’s nobody else around. And then she shows him the book. 

Zexion reins in his annoyance at yet another interruption to take a couple steps towards her and check the cover, and it all vanishes as he recognizes some of the runes engraved in the leather. 

“I have.” He answers, reaching to tap a finger on the tome’s spine. The magic flutters around it. 

The girl, Kairi, shifts her weight from foot to foot. “Is it real? This book, I mean.”

Zexion nods, cautious. “How much would you sell it for?” 

If it were another book he’d consider swapping it for an illusion, but true magic tomes require caution. They can be very picky, and it’s not every day that they change hands. 

“It’s not for sale.” Kairi replies. “But we can make a deal.” 

“What… kind of deal?” 

“Teach me magic. Then you can read the book.” 

Zexion blinks, taken aback by the proposal, and his first reaction is to say no. He cannot, he doesn’t have the time, his labor in the Organization is far too important. He’s a scholar and a scientist, however, and he’s heard some very interesting things about the magic of this World. 

“Would you really accept lessons from a stranger?” 

Kairi looks away, still holding the tome with a certain reverence that he cannot help but to approve of. 

“You aren’t from this world.” She says at last, but her voice is firm and now she’s holding his gaze. “And it may be years until I meet another person from outside. I have to learn.”

He doesn’t ask her why she knows about other worlds, he can't see any doubt in her words. 

“I can come once a week and teach you the basics. I’ll read the book while you practice.” Is what he settles for. The tome doesn’t look particularly heavy, he can probably finish it in three or four afternoons and get all he needs from its pages. 

Kairi beams, and the magic around the book ripples slightly. It’s unexpected in its power and Zexion can’t help but to stare. Most people barely have the potential to read a tome, much less to make it react, but so far the book its even masking Kairi’s presence. Now Zexion is curious. 

“On Fridays?” Kairi suggests. 

Zexion needs a moment to remember it’s Wednesday. There are a few tests he wants to run and there’s always the chance the Superior will need him, but he can probably spare that afternoon. 

“Very well.” He acquiesces. “I will come on Friday. My name is Zexion.” 

A moment later he weaves an illusion and vanishes, opening the corridor beneath a veil of invisibility. He doesn’t have to worry about the book anymore, not when a deal has been made. And he’s finally located the tome, that’s what matters most. He’s always been a scientist, but he discovered his potential for magic when he became a nobody, and ever since then that’s been another discipline to investigate. Not all worlds have magic and this wasn’t an opportunity he could ignore. 

 

Kairi remains in the alley for a good while after Zexion leaves, clutching the tome and steadying her nerves. She doesn’t know Zexion but what she said was true: it may be years until someone else comes. It may be years until Sora and Riku return, and she cannot simply wait. Not after all she’s seen, not among people that don’t believe other worlds exist. If she can learn magic maybe she can find Sora and Riku, or go with them the next time they leave. 

She won’t be left behind again, she vows, and for a moment she thinks she can feel the book thrum with power.

**Notes for the Chapter:**

> So this is the end of the first chapter! The whole thing with the book and magic is one of the plot thingies I’m using, but save for that we should walk next to canon for a few more chapters at least.  
> Updates will be regular and the first arc of the fic is fully planned out. Currently working on the second. I expect there will be 15-20 chapters (I put 17 just in case), but this is may change as I write them.


	2. Let us start with fire

**Notes for the Chapter:**

> So this is chapter two! Thank you all so much for the support <3

The silence in the laboratory is only broken by Zexion’s faint footsteps and the rustle of papers as he shifts his notes and checks at the various screens. There are many variables to account for and the simulation will take time to finish processing, so he knows he can devote some time to look for his first papers in magic. Illusion is only a branch, the one he’s best at, but maybe it will be better for a novice apprentice to start with something easier. He already knows Kairi has the potential for magic, the tome wouldn’t have reacted to her otherwise, he just hopes she won’t lose patience if it takes her some time to start affecting the world. 

One of the screens lights up, Zexion stashes the notes he’s chosen under his cloak and runs a few more tests. A few weeks at most and they should have a fully functioning human replica. 

Vexen appears just as he finishes comparing two charts and Zexion turns around. Most of the time he wouldn’t bother, but he knows Vexen is back from talking to their Superior. 

“He wasn’t dissatisfied with our progress.” The other scientist sighs.

Zexion can read what Vexen doesn’t say. Xemnas wasn’t satisfied, either, but science can’t be rushed. 

“We will not fail, Vexen.” Zexion vows, before another concern crosses his mind. “Marluxia?”

“Nothing new.” 

Zexion nods, looks at the time and keeps working. He can hear Vexen moving around and running a few analysis on the vessel for the replica, but they work in silence. Zexion doesn’t feel the need to talk if there’s nothing to be said and it’s only when it’s time for his appointment that he opens a corridor through the darkness and leaves, for the second time in a week, the World that Never Was. 

 

The Destiny Islands greet him with yet another beautiful day, and Zexion finds Kairi waiting by the alley they last spoke. She seems worried, but she grins as Zexion appears and lowers his hood. 

“Do you have any place we can study undisturbed?” Zexion asks her, glancing at the tome she has brought with her. Good. 

“Hello to you too.” Kairi frowns. “There is a beach not far from here, it’s usually empty.” She suggests. 

“It will do.” 

So Kairi leads the way in a short but relatively awkward walk. Zexion can feel her curiosity, so after a moment he decides to humor her. 

“Ask away.” 

“You’re not a chatty person, aren’t you?”

Zexion resists the urge to sigh. He’s never been talkative, not even before losing his heart, and he doesn’t really have many friends. The closest to that is Lexaeus, and even then he’s more of a big brother. 

“I am not good with words. Was this really your question?” He grumbles.

“No, but I was curious. How did you learn magic?”

That’s much better. 

“I studied.” Zexion tells her. “I found that I had the aptitude and hit the books. It’s like any other science.” 

Kairi nods. “Do I have the aptitude?”

Another smart question, so Zexion allows himself a small smile. 

“Yes. The tome reacts to you, you must have felt it.” 

“I thought it was my imagination.” 

“Most of the time it won’t be. At first it is complicated, then it will get easier.” 

They arrive to the beach not long after, and Zexion takes a look at the place before deciding that it will do. The chance of unexpected visits is negligible with his powers and the closeness to both sea and land will help the spells focus. 

“So,” he starts, as they sit on a pile of rocks, “magic is a science. There are laws and there are limits, but not many. It can be influenced by your heart, by your emotions and by your health, but that could become negligible with training.” 

Explaining the basics is simple enough, and Kairi listens intently. She has questions and takes notes, and Zexion doesn’t mind repeating himself or clarifying any point he has too. He’s brought his notes, but he knows the basics by heart and waits until Kairi’s concentration starts to weaken to stop with the theory. He may be doing all of this for the tome, but he is a scientist and being able to explain himself clearly is a point of pride for him. There’s also the fact that he loves magic, and he rarely has a chance to talk about it. 

“Now let us start with practical magic. Touch the tome, it will help you recall your power the first times, and concentrate.” He then slips her a page of his notes. “Read the runes and do the gestures, then imagine a small flame on the palm of your hand. It won’t burn you.” 

It takes Kairi three attempts to conjure a spark, four more to create something that could be called a flame, but it’s something and it’s magic and she’s grinning, and Zexion finds himself unexpectedly proud of her. Then he notices, gets serious again and clears his throat. 

“Now do it without touching the tome.” He asks her. “Concentrate just on the feeling of magic.” 

So she hands him the tome and focuses again. It takes her a few more tries and the spark is minimal, but it’s a beginning. Meanwhile, Zexion can start reading the old tome. It opens reluctantly, but between explanations and tips, and a couple more of basic spells he teaches Kairi, he manages to get through the first chapter. It’s not as comfortable as reading on the lab, but it’s something, and if he catches himself smiling a few times when Kairi finally gets the hang of creating fire, he will not admit it. Much less to himself. 

“You can keep my notes this week.” He tells her as the sun starts to set and he gives her the tome back. “Bring them back next week, however, and be careful with them.” 

“Really?” 

Zexion nods. “I’ll be here next Friday. Until then.” 

“Hey, wait!”

Zexion halts, the corridor of darkness appearing to his side. 

“Thank you.” 

The nobody smiles and vanishes, forcing himself to be serious again as he returns to the lab. Maybe he’s not read as much as he’d like, but he cannot get the feeling that he’s wasted his afternoon. It’s not that he can get many feelings, either, being a nobody and all that.

 

The laboratory is empty save Lexaeus, who leaves his chair when he appears. 

“Are the tests ready?” Zexion asks him, glancing at the screen. 

Leaxaeus nods. “Are you alright?” 

Zexion can see he’s pointing at the sand in his shoes and forces himself not to look in any way guilty. 

“Yes. Books, again.” 

It’s not a lie, not exactly, and Lexaeus doesn’t even frown much. 

“Any potential recruits?” He asks him. 

That wasn’t something Zexion had considered, not yet. 

“Perhaps.”

Lexaeus simply rests a hand on Zexion’s shoulder. He’s never been very expressive, but right now he looks worried. It’s eerie, how human they look even after losing their hearts to darkness. 

“Will you be going to Castle Oblivion?” The other asks at last.

Zexion waves his hand and the room around them shivers. Now they cannot be spied on. 

“Yes. We’ll need to be there to finish Marluxia’s replica.” 

“Be careful.”

 

Zexion dismisses the illusion when the other nobody leaves, but it still takes him a few moments to get back to work. Had it been any other than Lexaeus, Zexion would be angry, but the former guard has always been there for him. There are times Zexion feels that Lexaeus is the only other nobody he can fully trust. He’s not in bad terms with Vexen or Xaldin, but the former has always been loyal to science alone and the later is rarely in the labs. 

Then there’s the others, with Marluxia at the forefront. The replica, a masterpiece, should be enough to allow Zexion to position Vexen as a spy in Castle Oblivion. It’s disgusting how the Organization is starting to fall apart at the seams. There is not a fully formed conspiracy, not yet, but Zexion doesn’t know what he’ll do if the Superior falls. He burned the bridges to his old life, so he guesses he can only keep going forward.

**Notes for the Chapter:**

> So yeah, that’s the end of this chapter. I will try to update at least weekly on Saturdays and sometimes on Tuesdays too, depending on how many chapters I’ve written that week and my schedule and all that. I’m not really sure this story will only go for 17 chapters because the next one was supposed to be short and is now chapters 3 and 4, so we’ll see :)


	3. Science is taxing

**Notes for the Chapter:**

> Once again thank you for your support!  
> Behold Chapter 3:

It’s a matter of days until the Replica awakens, that’s what Vexen has told Larxene. It’s also what Zexion has told Marluxia every time he’s appeared on the laboratory at Castle Oblivion, and what he’ll probably have to tell them a good number of times. It’s not so much that they ask or look impatient, even if Zexion has already been reminded that having a fully-functioning copy of Riku is imperative, but that Larxene spends far too long walking around the lab and Marluxia is far too curious.

Zexion knows he could cloak the whole room in an illusion and work undisturbed, but that would be an unwelcome distraction to his concentration. Another one. So as soon as Vexen appears, Zexion leaves him in charge and vanishes before anybody can ask. It’s Monday, but he’s already changed the day of Kairi’s classes twice to keep the Organization's curiosity to a minimum. 

They have also changed the place, so the beach that welcomes him is far smaller that the one in the main island. 

“You’re early.” Kairi tells him, smiling widely as she shuffles the notes he’s left her.

Zexion, exhausted as he is, manages to smile back as he closes the corridor of darkness. He can’t help a yawn, however, an unwelcome reminder that he may not have a heart but he still has a body and sleeping is a necessity. He’s been running on half nights for close to a week in hopes of finishing the replica before Riku becomes a true threat and as the time from Kairi’s classes comes also from his sleep schedule, he’s starting to fear someone will notice. 

“I’m alright.” He tells her, however, as he cloaks the small island so that Kairi can practice without people noticing from the mainland. “What did you practice?”

Kairi shows him a thunder attack that is slowly becoming dangerous to something else than a patch of grass and then the illusion of a fireball. It’s not fully realistic, there’s something off about the shadows, but it’s decent enough and Zexion shows her how to imitate the lighting before taking the old magic tome.

It’s only when he nearly falls asleep for the third time that he decides that he’s going to waste the afternoon if he stays there. 

“You really are exhausted, aren’t you?” Kairi asks, her voice as amused as it’s worried. 

Zexion very pointedly doesn’t yawn. “A little. And as I cannot concentrate, I think I’ll check a lead on another book I may have located.” He tells her. “I shall be back before sunset.”

A shadow of fear crosses Kairi’s gaze and the illusion she’d been conjuring vanishes. 

“Can I go with you?” She blurts out, once again surprising Zexion. 

The nobody considers it for a moment, then shrugs. He doesn’t have strong feelings either way.

“Alright,” he acquiesces, “but bring the tome.”

“Why?” 

“It protects you from some forms of magic." He explains. "I’ll return in a minute, you’re going to need my spare cloak if you are to travel.”

Kairi clutches the old book, but nods. 

“Do you promise to be back?”

Zexion does, then opens a corridor to the World that Never Was. He feels Kairi’s gaze on his back even after he closes it behind him. 

She asked him about the corridors on their third class, trying to get him to teach her how to open one. 

“I am not sure I can.” He’d told her, and it had been true. The skill had come with the darkness, with the void that replaced his heart, and he’s been unable to replicate it with magic. It’s not that he hasn’t tried, as it’s a skill he’d love to keep when they finally get their hearts back, but so far all he has are theories. If Kairi tried it he isn’t sure about what would happen, especially because the protection from the book keeps hiding the darkness in her heart. It’s probably not much, that’s what Zexion suspects, but maybe it’s just enough. And if it isn’t, she can always get a Gummy ship. 

 

Zexion appears in his room, gets the spare cloak and returns to the Destiny Islands before a minute has gone by. He can see the relief in Kairi’s eyes as he steps out of the corridor and offers her a cloak. 

“There is darkness between the worlds,” he tells her, “the cloak will protect you.”

He stifles a yawn as he opens another corridor, then offers Kairi his hand. She doubts, he can see it, but then she steels herself and takes it. 

 

Zexion has never been to Hollow Bastion and all he has is half a map that Demyx obtained somehow and lost in a bet with Luxord. At least that’s what Lexaeus told Zexion as he handed it to him. 

“So, that’s supposed to be that building, right?” Kairi asks him, eyeing the map without much certainty. 

Zexion can only shrug. 

“For all we know, we could be on the other side of this world. But it does look similar.” He admits, before rotating the map. 

Hollow Bastion, for starters, it’s not how he’d expected. Hearless roam the streets, the few people around are far away, and he only knows that because his magic allows him to feel their ‘scent’, their presence, and he keeps getting the weird sensation that he knows about the place. 

“We will return to the Destiny Islands if we cannot find the place by sunset.” He promises Kairi. 

At least keeping an illusion around them that’s strong enough that heartless ignore them is managing to keep Zexion awake, so that’s good. It’s taking toll on his energy, though, when he considers that he’s also making both cloaks look like traveling cloaks, as well as obscuring his face and hair somewhat. As long as they don’t have to fight and they can retreat, however, that shouldn’t be a problem. 

“I have a hunch it’s that way.” He hears Kairi deadpan once they’ve explored enough streets that they can only continue one way. A lot of the streets are barricaded, in fact, and Kairi has already pointed out thay it looks very recent. 

“There’s people in this world.” Zexion tells her. It’s his abilities that alert him once they start being followed, and he shifts the illusion so that they look a couple of steps to the right than they really are. “And one of them’s following us.” 

Kairi flinches, suddenly nervous, then breathes out. 

“Let’s go back.”

“If you want to.” Zexion offers. “But even if they attack, we can defend ourselves. The inhabited area is not far.” 

Kairi glances at him, then looks at the sky. “Okay. But… tell me something. If the heartless attack, am I strong enough to fight them? With what I know.”

Zexion does her the courtesy of being honest. “If they are not particularly powerful and you are not surrounded, I’d say you could. Yes.” 

She looks relieved as she nods, then keeps walking, and Zexion tells her not long afterwards that they’re not being followed anymore. In fact, a moment later a girl in black shorts and a black top jumps down from a nearby building and starts waving at them. 

“I don’t appreciate being followed.” Zexion comments, politely enough that it’s clearly a threat. He feels the urge to trap her into an illusion just as he considered shifting the illusion so that he and Kairi vanished, but they still need the information.

Moreover, his words are enough to knock the smile off her face and she has the decency to look sheepish, even if her cheerful demeanor doesn’t fully vanish. 

“I needed to check you were people.” She explains. “And make sure that you got here safely. Are you new?”

Kairi looks at him, as if wondering what she should reveal, and Zexion encourages her with a gesture. 

“Okay…” She says. “We are looking for books. Old… books.” 

“An archive, or a bookshop, if there’s still something like it.” Zexion complements. 

The girl starts walking backwards, crosses her arms and then nods. “I know of someone with an archive of sorts. I can lead you to them.” She offers. 

Kairi and Zexion share a glance and she lowers his voice. 

“If she tries something, we can leave through a portal, right?”

Zexion nods and Kairi more or less shrugs, so he gestures at the unknown girl to lead the way. 

“Great!” The girl says. “Follow me. I’m Yuffie, from the Hollow Bastion Restoration Committee.”

**Notes for the Chapter:**

> So, so, so. This chapter was meant to be much shorter, but then the Hollow Bastion Restoration Committee decided to add themselves to the plot and suddenly more things are happening.  
> I can also confirm that this story is chronologically set during Chain of Memories and, while this chapter is more or less a bridge chapter, there are a couple of points that do become important later :3


	4. Of machines and memories

**Notes for the Chapter:**

> Behold! Chapter 4 is here, introducing a few more thingies.

The Hollow Bastion Restoration Committee is not so much a committee as a small gathering of people in an unassuming house, drawing over an enourmous sheet of paper what seems to be a map. Zexion cannot see much more before the other two people in the room move to stare at them, and it’s then than Yuffie introduces them. 

“This is Merlin’s house, he has books.” She points out. “He’ll probably come back later, so he can show you. But they’re magic books, so you really shouldn’t go upstairs without permission.” She adds, her smile apologetic. 

Kairi and Zexion share a look and she smiles, but before they can say anything Yuffie keeps on talking. 

“The man over there in front of the map is Leon, he’s a fighter, and the other is Cid.” She introduces them. “Boys, these are…”

“Kairi,” she tells them, smiling brightly. She’s still right next to Zexion, however, probably in case something goes wrong. 

“I am Zexion.” He introduces himself. “Do you know how long will it take for Merlin to…?”

He doesn’t finish the sentence. Just as Yuffie starts telling the other two how Zexion and Kairi had realized they were being followed and they could be a good asset for the Committee, the light coming through the window changes, Cid moves and Zexion sees a computer. 

It’s relatively outdated, but it’s a computer nonetheless and someone, probably Cid by the way he’s looking at him, had just been coding something. A moment later Zexion is peeking at the screen, his curiosity getting the best of him. He’s dismissed the illusion that masked his position, but he’s confident his cloak is still looking like a common travel coat. 

“Be careful…” Cid starts, but Zexion knows enough lab manners not to touch another’s computer just because. He can read the code, however, and what he sees is certainly interesting. 

“A defense system?” 

The room grows silent and Zexion turns to see Yuffie beaming, Leon crossing his arms and Cid frowning, even if a moment later he starts to smile. Kairi is once more next to him, but not as close anymore. 

“We’re working on it. Something that can protect this place. We’re trying to rebuild this world.” Cid explains. “You think you could help us?” 

“We cannot be here for long.” Zexion tells them, but his eyes haven’t left the screen and Yuffie is grinning even more. “This is against heartless, right?” 

“And nobodies.” Leon explains. “The heart becomes a heartless, the body…” 

A Nobody. They don’t have to explain that, especially not to him, but maybe Kairi didn’t know. 

“We don’t know how long it’ll take Merlin to come back, but we’ll take all the help we can get.” Cid offers. 

Zexion looks at Kairi, who shrugs, apparently as curious as he is, and in the end they decide to wait until nightfall. Kairi promises him she doesn’t mind, so meanwhile Zexion will help Cid. He keeps an eye on everyone, but it’s a matter of minutes until Kairi is sitting with Yuffie and Leon, talking about the heartless and a few things more he doesn’t catch. In truth, his attention is now with Cid and his code, because for starters it’s good code and if he can manage to finish a defense system against nobodies, it could make things annoying, at the very least, for the Organization. He can’t allow that.

It will probably be a while until the system is ready, he decides once it’s late enough and Merlin hasn’t appeared, but he’s got a few ideas to ensure it doesn’t detect human-looking nobodies. He’ll have to be back, however, and not only to check Merlin’s books. 

The sunset greets them in the Destiny Islands and as they set foot on the small island, Kairi’s expression goes from happy to pensive. 

“Is something the matter?” Zexion asks her, hiding a yawn as he summons the corridor to take him back to the castle. 

Kairi nods. “It’s just… I was wondering, what if Hollow Bastion is my home world?” 

Zexion tilts his head. “I thought you were an islander.”

“I was born somewhere else.” Kairi explains. “But… I have no memories from that. I think it’s because the world fell to darkness. I wish I could remember.” 

Zexion closes the corridor and sits on the closest palm tree, thinking about her words. 

“Would you like to remember?” He offers. 

Kairi gapes at him. “Can you do that?” 

“Yes. But we’d both see your memories.” He adds. “Think about it, tell me next week.” He offers. 

All in all, he’s curious about Kairi, and he’s basically skipped one of her classes, so it is only fair. It’s worth noting that if she lets him see her memories, he’ll probably be able to bypass her tome’s protection and see how much darkness there really is in her heart. The Organization could do with another magician. 

Moreover, he’s sure he can do it. He’s trapped a fair number of people in their own memories during battle, and he has watched his own memories when he feared he’d forgotten something. He’s not Naminé, he cannot affect them, but he’s still a master illusionist. 

“Wait. Let’s do it. But if you can see my memories, I want to see yours too. You never talk about yourself.” 

Zexion stops. He’d just made an offer and suddenly it’s something close a trade and he’s curious, yes, but is he curious enough?

Yes, yes he is. So he gestures for her to sit next to him as he takes the Lexicon out. 

“Concentrate on your furthest memory.” Zexion asks her. “Close your eyes, give me your hand, and don’t let go.” 

The pages flare, and suddenly the Destiny Islands vanish. 

 

There is darkness all around them. There’s the sound of the sea. Kairi shivers, Zexion moves his hand to ensure she doesn’t move away. She could get hurt if she does, no matter how careful he is. The sound vanishes and then there’s a cobbled street. It’s too far away, so Zexion moves to another memory, something close enough to that first one. It’s the Destiny Islands again. They disappear once more, Zexion whispers a word and suddenly they’re back on the cobbled street. There are flashes of an archway, of a market square he knows far too well, and for a second the memory of Radiant Garden throws him off-balance. They return to the Destiny Islands again, and there’s a woman with blue hair, and a small Kairi touching a Keyblade, and Zexion is now gaping because the illusion falls around them as he realizes three very important things. 

The first is, he’s exhausted. The second, slightly more worrying, is that Kairi has the potential to summon a Keyblade. The memory was not false, it didn’t feel false, so she should be an asset to the Organization. But she can’t be, because there is absolutely no darkness in her heart and that should be impossible, but Zexion knows what that means and, before Kairi can ask anything else, Zexion decides to fulfill his part of the deal. Mainly because he needs to think this carefully. 

So the Destiny Islands disappear once more, and they are back in the same square. This time, however, he’s there with Lexaeus, who was Aeleus by then, and he’s a child with bright blue eyes who cannot imagine the future. Then there’s the castle, there’s Ansem the Wise, and Zexion skips the memory because his chest is doing something it shouldn’t be able to do without a heart. There’s his first lab coat, and there has to be something else he can show her. He isn’t sure, and the illusion is dispelled a moment later.

Kairi has to hold him so that he doesn’t fall over. His head hurts, he needs to think, he’s got work to do and he ends up opening the corridor with unusual clumsiness. 

“It appears we both come from a world called Radiant Garden. It was destroyed.” He tells Kairi through the headache. “I’ll be back on Saturday, we can talk more then.”

He’s got the feeling, as he leaves the Islands, that he’s made a couple of very bad mistakes.

**Notes for the Chapter:**

> And this is chapter 4. The cat's out of the bag, there's only one more chapter to finish the introduction and setting of the fic itself. From there onward it's things happening :3
> 
> By the way, I know there haven't been chapters from Kairi's point of view. They'll appear as soon as Zexion is not the one with most knowledge of what's happening. Some have been written already :3


	5. Such a small gesture

**Notes for the Chapter:**

> Hey, this week I could update twice! Here, have some feelings.

Vexen is no more and Zexion is glad he doesn’t have a heart to feel how oppresive the lab has become. Marluxia and Larxene are not breathing down on his neck anymore, and there’s just the final touches left for the Replica to awaken, but if something fails with its body Zexion fears the consequences. He can only hope Vexen did a good job. 

Castle Oblivion is not safe anymore, however, and that accounts for the presence of both Sora and Riku within its walls. At least Zexion has Lexaeus, and he asks him to stand guard next to the Replica as he leaves to consult Naminé. Zexion doesn’t bother to walk, he simply appears outside of her room and knocks. They haven’t talked much, but Zexion could recognize that metaphorical scent anywhere. It’s pure light among so much darkness, and for the briefest of seconds until Zexion lowers his hood, as he sees the fear on her face, he feels the urge to calm her down. 

“I am not Marluxia.” He says instead, glancing around the room and at the drawings as he makes sure they are alone. He waves his hand in a quasy-dismissive gesture and the room ripples, an illusion appearing so that they can talk freely. 

“You’re Zexion.” Naminé answers, as she offers him a seat. Zexion doesn’t take it. 

“Do not worry, I am not here to harm you.” He tells her, however, hoping to sound calming. “I just want to ask you a few questions.” 

“The memories are ready.” She replies. 

“I had no doubts. But it’s not only about that.” 

“Oh?”

Zexion closes his eyes and pictures Kairi. When he opens them, there’s Naminé in front of him. 

“You shouldn’t be able to exist.” He tells her, voice serene. “Not both at the same time. It… shouldn’t be possible.”

He’s tried to be calming, but Naminé is nothing if not outright terrified now. 

“Please don’t hurt her. Please.” 

Zexion feels her eyes on his, but he doesn’t look away. 

“I won’t.” He admits at last. 

She doesn’t quite look like she believes him. 

“Why?” She asks him, her voice small and confused. 

Zexion isn’t sure, in truth. But he’s been watching what remains of his own memories for days, both his childhood and his investigations, as well as the moment he and the other apprentices betrayed Ansem the Wise. He’s watched the darkness consume his heart, awakening the magic and the power and taking away all the emotions that he’s certainly glad he can only remember. And he’s watched Kairi take his hand and walk by his side to another world. It’s maddening, how such a small gesture matters to him now. 

He checks the illusion once more before replying to Naminé’s question. 

“Because she has trusted me.” He admits. Because he can only go forward now, but one heinous betrayal to haunt him forever is more than enough. 

Naminé slowly smiles and it’s like watching the sun appear from behind a stormy sky. 

“What do you want to know, Zexion?” 

He stands up and walks towards one of the pictures. It’s Riku and Sora, but Kairi is also there. It’s not one of the drawings he remembers from his previous visit.

“Are they friends?” 

Naminé nods. She’s still smiling and somehow it seems far more real than anything he’s seen on another nobody. 

“Best friends.” She replies. The smile then fades. “But Riku is fighting his own darkness and Sora is fighting the darkness in others.” 

Sora is fighting them, they are the darkness that light will always oppose. He guesses the light includes Kairi too. 

“I will bring the replica tomorrow.” He tells Naminé. “Are you in need of anything?” 

Naminé smiles tightly and Zexion vanishes. He cannot free her, unfortunately. He does drop by a small shop in the Destiny Islands to buy her good drawing paper, however, before he heads to the small island where he’s meant to meet Kairi. 

 

“I apologize for my behavior the last time we met.” He tells her as he appears from the corridor of darkness. 

Kairi shakes her head. “Don’t worry. Are you better?” 

It’s not an easy question, so he settles for a small truth. 

“I slept last night.” He admits, sitting cross-legged on the sand. “So, shall we talk about Radiant Garden?” 

“Are you sure?” She asks him as she sits next to him. “You looked pained.” 

“It’s the memories.” He admits. 

So he tells her about the squares and streets, about the market and all the sounds and about that small ice-cream shop where he and his mentor used to buy ice-cream. About learning from him and, even though vaguely, about the other apprentices. 

“What happened?” Kairi asks. She looks worried. 

“The world was consumed by darkness.” 

Kairi doesn’t press and Zexion watches the sea for a few moments. If all goes well, he could finish the magic tome that same afternoon. He tells himself it’s for the best. 

Then Kairi stretches her hand towards the horizon, there’s a very distinctive shimmer on the edge of Zexion’s vision and he has to resist the urge to edge away as a keyblade materializes on Kairi’s hand. 

“I wanted to show you this.” She grins. 

Zexion freezes until he manages to convince himself that he’s too regal to gape. 

“How?” He manages to ask, battling the awe and the fear. 

“The moment I knew I could, it was like doing magic.” She admits. “It… felt right.” 

Zexion slowly nods. A part of him is earnestly curious, he’s never had the chance to simply talk with a wielder of the keyblade before. The rest of him knows this is a very serious problem. 

“So, what are you going to do now? Do you still intend for me to teach you magic?” He asks her, at last, when he can face her. 

“Yes!”

“I… guess you could use the Keyblade to focus your magic.” He suggests, and she grins. 

“I’ve already tried. It works.”

So Zexion brings out the Lexicon, lets it float over his left hand for a moment and then rises. 

“Show me.” He tells her, as the illusion of a few heartless appear next to them. 

She flinches, but she jumps upwards and rushes towards them. Zexion makes them move away. 

“They’re illusions.” He calms her. “So hit them with magic.” 

 

“I guess this means I can travel between worlds now.” She tells him once she exhausts herself sending ice spells at a palm tree. 

Zexion, who is very pointedly not reading the last chapter of the tome, frowns. 

“All I have are guesses.” He admits. “I am not familiar with the way keyblades work. If you are not travelling through the darkness between worlds, and I am not sure you’d be able to, wouldn’t you need a Gummy ship?”

Kairi grins. 

“Why don’t we go to Hollow Bastion?” She asks him, not at all answering his question. “We promised Yuffie we’d be back.” 

Zexion is starting to worry, but he flicks his wrist and the corridor appears. Once more Kairi takes his hand, but this time there’s no hesitation and Zexion can’t help but remember his conversation with Naminé. And to think it had all seemed a good idea once.

**Notes for the Chapter:**

> And there we go. It appears I'm writing about ripple effects, at least in terms of inter-character relationships. One small thing, one small gesture of trust, and things slowly start to change.


	6. And thus we fly

The darkness closes silently behind them and Kairi is more than glad to see that they’ve appeared really close to the Hollow Bastion Restoration Committee. She can understand that opening a portal inside someone’s home, especially if that someone is a mage, is a very bad idea, but the streets crawling with heartless and nobodies still make her uneasy. 

Besides her Zexion is thoughtful, even more than he usually is. Kairi had expected him to be curious, or at least happy when she showed him the Keyblade, but he had flinched. She’s not worried for herself, not really, but given that and the fact that he’s finishing the magic book she can’t help the feeling she’s going to get left behind again. Yuffie is hopping towards them, though, so Kairi can’t find it in herself to be sad for long. 

“Come in, come in.” Yuffie invites them, stopping to let Kairi hug her. “Leon is in there and Merlin has just arrived.”

At the mention of the mage Kairi can feel Zexion’s sudden attention and she can’t help smiling. 

“Go, I’ll stay with Yuffie, I’ll be safe.” She tells him. 

Given the way he tends to light up when talking about magic, Kairi doesn’t doubt that meeting the other wizard will cheer him up at least a little. And she can chat with the ninja and her friends meanwhile. 

“We found something.” Yuffie tells her, as soon as she sits on the map table. It’s empty this time, but Leon is making tea. “Cid is tinkering with it, but it’s functional.”

“You’re not serious.” Kairi grins, but Yuffie is grinning harder and now Kairi is laughing too. 

It’s then that Cid appears from a back door and waves at them, and as soon as they follow him Kairi gets to see the cutest small Gummy Ship. Well, maybe not the cutest, and it’s battered and it looks like it’s weathered a hurricane or two, and it needs some painting and maybe it looks kind of cranky but it’s a Gummy Ship and…

“And we're lending it to you.” Yuffie tells her. “So that you can find your friends. We have our hands full with Hollow Bastion and you have people out there that need you.” 

Kairi hugs her and holds her tight, and then motions for Leon and Cid to join the hug. She can see Zexion smiling from one of the windows, looking slightly less thoughtful, and she waves at him. He waves back, nodding appreciatively at the ship before returning to his conversation. 

“So, have you learnt more magic?” Yuffie asks her once they’re back inside. 

Kairi didn’t think her grin could be wider, but the expression on Yuffie’s face once she summons her Keyblade is a sight to behold. 

“I’m gonna need to train a little.” She admits. “But now I can help too!” 

“Yuffie and I could make some kind of obstacle course or something to help you practice.” Leon offers. “I guess Cid needs to keep working on the defense system.”

“Why? Weren’t you making good progress?”

“Yeah.” Cid sighs. “And your friend helped a lot, but it’s still a hard job.”

It is then that Zexion appears in the stairs.

“I am finished here.” He tells Kairi. “Do you want to go back, or do I come by later? Or would you rather use the Gummy Ship?” 

“I’m gonna take the ship. But wait.” She adds. “Can you come with me?” 

Zexion tilts his head just a little. 

“In case I make a mistake.” She clarifies. “Or I get lost.” 

“Very well.” He acquiesces. “Shall we go?”

 

The ship is supposedly small, but Kairi has never seen one before. It’s also supposed to be a repair job that’s functional, not pretty. She still likes it. There are two seats, it’s big enough that she can hide it in the island and when Leon finishes with the instructions, Kairi decides to try it. 

As promised, Zexion is there, sitting on the second seat. His Book of Retribution rests open on his hand, the pages shifting and passing as if moved by a nonexistent wind. It was creepy at first, but now Kairi is used to it. 

“We’re going to leave this world.” Kairi tells him. “I’m going to leave a world on my own. Now I can travel.” She repeats. 

She can hardly believe it. It’s like a dream and she cannot help the fear that she’s going to wake up in a moment. That everything has been a dream, everything since the moment she met Zexion. 

“Now you can travel.” He echoes, as Hollow Bastion slowly gets smaller. 

Then she raises the Keyblade and opens a portal, and she feels the Keyblade’s power like static in her hand. It feels natural. 

 

They manage to land in the Destiny Islands, and Kairi is laughing and nearly crying because they nearly crashed and Zexion had to cloak the ship so that the islanders didn’t see them, but they’ve done it and she’s traveled between worlds and she has a ship. She leaves the seat with a grin and when Zexion leaves his she walks over to him and hugs him. It’s only a moment because he freezes, and she immediately lets go. 

“I’m sorry.” She tells him. 

He takes a moment to answer, then slowly shakes his head. 

“Do not worry.” He says, as his book vanishes from his hands. “Don’t think of it.”

“We got here. Thanks for trusting my driving skills.” She says, sitting on the gummy ship. Her legs are trembling. 

Zexion’s hair is a bit disheveled, now that she looks at him, and he’s not walking with much of a sure step. Still, he nods. 

“They are decent enough.” He replies. He doesn’t sit down, but leans on the ship. 

The sun is setting on the horizon and the red light is beautiful. It hurts Kairi to break the moment, but she has to ask. 

“Will I see you again?” 

Zexion doesn’t answer immediately. His book is now in his hands, but it’s closed. The air is still around him. 

“I will teach you one last class, if you want to, next week. Afterwards, I intend to help the Hollow Bastion Committee with their defense mechanism. If you go to their world, we may meet.” He suggests. 

He doesn’t look sad, he doesn’t look anything at all. So Kairi nods, and as he vanishes in a corridor of darkness, Kairi tries to summon back her optimism. She has her keyblade, and one last class, and she supposes it will have to be enough. He’s not her friend, he guesses, like Riku and Sora are. He’s just her magic teacher, and their deal is now complete. 

She settles for the hope they’ll meet at Hollow Bastion, and maybe then in other worlds, because now she can fight too, and Sora and Riku are out there somewhere. Still, she’ll miss Zexion. Someday, she promises herself, she’ll introduce him to her friends.


	7. The flooded fortress

**Notes for the Chapter:**

> Hey, hi there, I'm back! Life's been hectic and I'm very much behind schedule but well lol. Here, have a new chapter, and new updates will go once every two weeks until everything's back under control. 
> 
> Enjoy!

Selphie and Yuffie become friends in a matter of minutes, and Kairi is grinning as she sees the fear disappear from her friend’s face at last. Selphie hadn’t believed her until she’d shown her the Keyblade and when she’d asked Kairi to take her to another world, to prove she wasn’t making everything up, she’d obliged. Apparently, seeing that there were people in other worlds that were as human as her had been confusing, but she was getting used to it quite fast. 

Cid and Leon were there too, looming over the computer and frowning furiously. 

“It should work.” Cid grumbles. “The radar is operative and we have mapped a good part of the city, but there are still many areas we don’t know.” 

It’s then that Kairi approaches. 

“How many?”

Cid and Leon trade a glance, then Cid passes a hand through his hair and decides to reply. 

“We can’t know for certain.” 

Kairi simply nods and lets them return to their work, heading upstairs to meet Merlin. 

After her last class with Zexion, he’d suggested she ask Merlin for help. He was a wizard, after all, and he was already helping the Committee. But the door is closed and Kairi sighs, heading towards her Gummy Ship. 

“I’ll be back.” She tells Selphie, and then gets paper and a pencil on her way out. “I’m gonna map the area around the fortress.”

Leon asks her to be careful, Kairi smiles, and then takes off. None of them have ever gotten close to the fortress, surrounded as it is by hundreds of heartless, and Kairi is no exception. But if she can draw the area around it, it’s something. Usually it’s Yuffie drawing next to her, but Kairi doesn’t want to leave Selphie alone. 

She’s on her way back when she sees a corridor of darkness open on one of the balconies of the fortress. She gets closer, curious to see what steps out, and a moment later she recognizes a certain unmistakable black cloak. The figure doesn’t see her, but Kairi lands on the balcony a minute or so later and decides to follow him. What’s Zexion doing there? 

As soon as she leaves the gummy ship the darkness of so many heartless hits her, leaving her disoriented for the briefest of seconds. Then she stills herself and keeps walking. There are no heartless on the room adjacent to the balcony but that changes as soon as she thinks about it and she summons her Keyblade. There’s only three of them, all shadows, and a minute later they’ve all disappeared. 

The following room isn’t empty either and Kairi decides to close the door as soon as she sees the group of dusks turn their heads towards her. She can hear their steps, however, and now she’s worried. Where’s Zexion? Maybe he’s used his illusions to travel undisturbed, but what if… 

One of the dusks hits the door and Kairi shakes her head. He’ll probably be okay. It’s her that should return to the gummy ship. Still, she can try the next room, right? So she takes a deep breath, yells a challenge and rushes towards the dusks. She can feel her heartbeat in her head. She slashes at the first dusk and it simply vanishes, and when she looks around again Zexion appears from thin air. 

“Those were my dusks.” Kairi tells him, far too relieved to sound angry. 

Zexion arches an eyebrow, apparently amused, and the dusks reappear. Kairi jumps back, glaring at him, and he waves a hand and they vanish once more. 

“Don’t do that.” She asks him. 

His smirk doesn’t vanish, but he nods. “You should not be here.” He says, however. 

“You shouldn’t be here either.” She points out. “What happens?”

He takes a moment to answer, his expression devoid of feeling as he tilts his head. Kairi feels the urge to take a step back, but she’s known Zexion for months. 

“I am not your teacher anymore.” He says, at last. 

Kairi huffs. “But you are my friend and this place is dangerous.” 

Zexion blinks, apparently taken aback by her words. 

“What will happen if I ask you not to follow me?” 

“This place is infested with heartless and nobodies.” Kairi tells him. “It’s dangerous! Even for you!”

“So you will follow me.” Zexion accepts. “I see. I cannot guarantee your protection, but do as you will.” He acquiescenes, before offering her his hand. “Shall I cloak our presence?”

Kairi huffs. She refuses to be afraid of him and she won’t be left behind again, so she takes his hand. It’s colder than hers, but his grip is gentle as the air around them shimmers. 

“Given how many heartless there are, however, we may need to fight some.” He warns her. 

Kairi nods. “Alright. But you haven’t answered my question.” 

Zexion seems to consider it, then makes a wide gesture that encompasses the whole room. Maybe the whole building. 

“According to Cid and Leon, this world was once Radiant Garden.” He explains. “I merely desired to check it.” 

Kairi stares at him for a moment, everything too unexpected for her to process it immediately. Is this really her birth world? This desolated place, managing to survive because less than a dozen people have decided to try? Eternally overrun with heartless? 

“That was my reaction too.” Zexion comments. 

“And… how do you mean to check if this is Radiant Garden?” She asks him, when she’s finally able to speak again.

“I remember the castle.” He explains. “If this is Radiant Garden, there are laboratories in the basement. They are probably a ruin and they must have been stripped bare, but some part of them should still remain. If the castle’s layout checks out and the laboratories are there, then this is the corpse of Radiant Garden.” 

“And if they aren’t?”

“Then Radiant Garden is somewhere in the Realm of Darkness.”

“And it can still be saved.” Kairi points out. 

Zexion glances at her, then slowly nods and leads the way. He seems to know where he’s going, and he stops a few times so that she can defeat minor heartless that cross their path, but they keep a steady rhythm until they arrive to a descending stairway. They stop then, and Kairi holds Zexion’s hand tighter. When he turns to look at her, she smiles. 

“I’m here.” 

Zexion doesn’t smile back, but he presses her hand somewhat reassuringly before pressing the door. 

It opens silently.


End file.
